trojan.spyeye not detected!

I just want to say i had Eset Antivirus 4.0.424.0 and the latest virus signatures but the virusscanner didn't detect trojan.spyeye who infected my computer and stole my passwords.

I knew i had trojan.spyeye because my double accent(¨¨) didn't work well in word. I googled and saw I may be infected with this botnetvirus.
I am a bit dissapointed in ESET. How is it possible that this virusscanner didn't detect such a threat

Thanks to MBAM the spyware got deleted.

 

1, there's nothing like 100% protection against threats
2, without knowing what was detected by MBAM, it's hard to tell if a fully updated EAV missed malware or if it were just some registry keys, other remnants or FP detected by MBAM
3, I'd suggest emailing ESET's malware lab as per the instructions here and enclosing a SysInspector for perusal if you suspect that your computer has been infected despite having the most current signature db installed.